液压凿岩台车油箱改造及热平衡计算分析

为解决三臂液压凿岩台车油箱改造问题,使液压油箱在改造后能够满足设备使用要求,并保证液压油箱容量及系统散热性能,需计算油箱容量是否满足使用需求,验证液压系统热平衡是否合理。对于液压油箱容量方面,分别从液压油泵排量,油缸及油管的储油量,使用过程中油箱液面的变化量3个方面计算分析了液压油箱的容量问题,验证了改造后液压油箱容量满足使用要求;对于系统热平衡方面,分别计算了液压系统的动力机构发热功率、液压油箱散热功率及水冷散热功率,结合理论计算得到了解决散热问题的方法。液压凿岩台车改造后经过工厂及工业性试验,并通过实践检验了其理论计算的合理性,以期为其他设备的升级改造提供一定的借鉴。     

9000 HP绿色环保型海洋平台供应船设计与研究

介绍在建9 000 HP海洋平台供应船设计中对主尺度、总布置、型线设计、电力推进系统、燃油驳运及货油输送系统、甲醇系统、对外消防系统,以及动力定位系统等设计技术问题的处理.     

Impacts of fuel quality on indoor environment onboard a ship: From policy to practice

Environmental considerations, concerning the negative impacts of ship exhaust gases and particles on ambient air quality, are behind the requirements of cleaner marine fuels currently applied in designated emission control areas (ECAs). We investigated the impact of a ship operating on two types of fuel on the indoor air quality onboard. Gaseous and particulate air pollutants were measured in the engine room and the accommodation sections on-board an icebreaker operating first on Heavy Fuel Oil (HFO, 1%-S), and later Marine Diesel Oil (MDO, 0.1%-S). Statistically significant decrease of SO₂, NOx, PM_2.5 and particle number concentration were observed when the ship was operating on MDO. Due to the higher content of alkylated PAHs in MDO compared to HFO, the concentration of PAHs increased during operation on MDO. The particulate PAHs classified as carcinogens, were similar to or lower in the MDO campaign. Chemical analysis of PM_2.5 revealed that the particles consisted mainly of organic carbon and sulfate, although the fraction of metals was quite large in particles from the engine room. Principal Component Analysis of all measured parameters showed a clear difference between HFO and MDO fuel on the indoor environmental quality on-board the ship. This empirical study poses a first example on how environmental policy-making impacts not only the primary target at a global level, but also brings unexpected localized benefits at workplace level. The study emphasizes the need of further investigations on the impact of new marine fuels and technologies on the indoor air environments on board.     

液化气船C型液罐安装关键技术与控制要点

以实际建造的液化气运输加注船为背景，通过吊装方案确定、鞍座裕量修整、罐体落座步骤、环氧浇注固定等方面对C型液罐进行细致研究，总结整个安装过程中的关键技术及控制要点，为今后提高同类型船舶建造效率积累经验。     

Ship motion-sloshing interaction using a field method

Even in relatively calm waters, low amplitude wave-induced motions of an LNG carrier may induce large amplitude liquid sloshing inside the ship's partially filled tanks, and the interaction between ship motions and sloshing may affect the ship's seekeeping properties. A computational procedure, here referred to as the RANS-RANS method, was developed to account for this interaction, and this method was then employed to predict the free surface flow inside the tanks and the corresponding motions of the ship in regular head and beam waves. This method coupled a compressible VoF technique with a generic wave generation and absorption scheme to obtain wave-induced ship motions with and without considering the effects of sloshing in the ship's tanks. Systematic grid studies were performed to obtain a sufficiently fine grid needed to yield converging predictions. The resulting wave patterns, ship motions, and internal sloshing elevations were compared with results obtained from a computational method, here referred to as the RANS-BEM method, that relied on a boundary element method to obtain ship motions. This RANS-RANS method was validated against model test measurements.     

Analysis on acoustic performance of floating raft vibration isolation system with liquid tank北大核心CSCD

［Objective］This paper aims to establish a dynamic model of a floating raft vibration isolation system with a liquid tank in order to study the mass effect of the liquid medium, tank form, structural stiffness and loading rate on acoustic performance. ［Methods］A floating raft system with a cuboidal or cylindrical liquid tank is taken as the research object, and a fluid-structure coupling finite element dynamic model is established. The dynamic force transmission rate and power flow are then used to evaluate the acoustic performance of the system. The influence of the mass effect of the liquid medium, tank form, structural stiffness and loading rate of tank volume on the acoustic performance of the floating raft system are analyzed.［Results］The results show similar laws obtained through the calculation and analysis of the floating raft system with two types of tanks. The structural stiffness of the tank affects the mass effect of the liquid medium in the tank to a certain extent. ［Conclusions］If full advantage is to be taken of the liquid mass effect in the tank with a large loading rate to improve the acoustic performance of the floating raft system, the design of the liquid tank and raft structure must have sufficient stiffness. In addition, under the condition that the floating raft structure has sufficient stiffness, its acoustic performance will improve significantly as the tank loading rate increases in the relevant low frequency range. © 2022 Journal of Clinical Hepatology. All rights reserved.     

沥青路面车辙隆起变化规律浅析

车辙是目前高速公路沥青路面主要病害之一,通过对试验路钻取芯样,分别测量芯样的高度、毛体积密度、油石比、级配等,得出荷载作用不同位置处相应指标的变化规律,为高速公路沥青路面车辙研究提供参考。     

柔性表皮减阻性能试验和减阻机理探索

对以中国化工新材料总公司海洋化工研究院为主开发的聚脲类等柔性表皮试样在循环水槽中进行阻力测试,并据此修改配料,最后得到的试样能减阻13～15%.本文也从数学上对柔性表皮具有减阻功能的机理进行了推证.     

鲁宁输油管道经济清管周期的确定

介绍了原油在输送过程中蜡的析出规律,建立了当量管径与输油天数的数学模型,从而确定出管道最佳的经济清管周期。     

格拉管线被第三方损坏的抢修实践

某日 ,格拉管线正在输送汽油时 ,终端拉萨分输站的进站压力和流量突然同时大幅度下降 ,初步判定为管线发生了破裂跑油故障 ,经巡线查实 ,在距该站下行方向 30 0 0km处的管线被施工的挖掘机挖破而大量跑油 ,经两昼夜的紧急抢修恢复了正常输油